The reordering option in library gplots : heatmap.2 is broken. Re-ordering of
the dendrogram is supposed to work by providing a vector of ordering weighs in
Rowv. However, the tests in line 131 and 174 are not adequate for Rowv being a
vector and therefore break the code. The same is probably true for Colv. Also,
there is a typo in line 137 ("dedrogram" instead of "dendrogram").